Recently, various light-emitting apparatuses having a plurality of light-emitting devices on a substrate have been developed. The light-emitting devices used in such light emitting apparatuses tend to exhibit variations in characteristics such as a color (wavelength) and a light output (power) regarding each wafer (i.e., each manufacturing lot) and/or manufacturing equipment used. Because of this, the light-emitting devices are first classified into various ranks according to their color and output, etc. Then, the light-emitting devices at the same rank are used for the same light-emitting apparatus. This promotes the characteristics of the light-emitting device to be made uniform.
However, exclusive use of light-emitting devices at a specific rank means that only some of the light-emitting devices manufactured are going to be used, which leads to a decrease in yield of the light-emitting devices. In a light-emitting apparatus using a plurality of light-emitting devices, in particular, the light-emitting devices account for a large percentage of the total cost. If the light-emitting devices at a specific rank are exclusively used, their yield decreases and their cost increases. Accordingly, the following technology has been previously disclosed.
Patent Literature 1, for example, discloses a display having a plurality of LED pairs modulated simultaneously, wherein the LED pairs include a combination of LEDs having an approximately symmetrical luminous intensity with regard to the center of a luminous intensity distribution formed between a region having the maximum luminosity and a region having the minimum luminosity of the LEDs.
In addition, Patent Literature 2 discloses a method for mounting LED chips which are mounted like a grid on a substrate, including the step of arranging LED chips of the same manufacturing lot in a way the LED chips are not adjacent to each other.
Furthermore, Patent Literature 3 discloses a method for manufacturing a display, including the steps of dividing a wafer having arranged light-emitting devices into blocks; determining averages of characteristics such as a wavelength and brightness of the light-emitting devices in each block; and rearranging and disposing each block on a relay substrate so as to make the averages of characteristics distributed uniformly over the surface of the relay substrate.